The last decade, the biological and biomedical scientific landscape has seen the increase in use and applications of omics technologies. These technologies provide methods that allow for a comprehensive description of nearly all components within the cell. Microalgae not only play an important ecological role, but are also of commercial importance and therefore call for an in depth knowledge of basic biological functions. Knowledge of separate algal subsystems has gradually become available, but the challenge remains to integrate data obtained from these subsystems and from different levels of biological organization. Systems biology is a discipline that aims at this integration. In this paper, the current status of omics in algae is reviewed. At the lowest level, genome studies and the use of microarrays seem to have found widespread acceptance in algal research. At higher level such as the proteome and metabolome, however, very few omic studies have been carried out in algae so far. Moreover, the need arises for the construction of computer databases to store obtained information in a systematic way. To illustrate the use and especially the future needs of algal omics in a systems biological context, a case study is presented in which a freshwater alga was subjected to heavy metal stress and toxicity endpoints were monitored on different levels of biological organization.